serialization/eigen: account specifically for storage order

- options is ENUM which could contain further information about alignment https://eigen.tuxfamily.org/dox-3.3/group__enums.html#gaacded1a18ae58b0f554751f6cdf9eb13

Author: fabinsch

include/proxsuite/serialization/eigen.hpp

@@ -30,9 +30,15 @@ save(
 {
   Eigen::Index rows = m.rows();
   Eigen::Index cols = m.cols();
-  ar(rows);
-  ar(cols);
-  ar(_Options);
+  ar(CEREAL_NVP(rows));
+  ar(CEREAL_NVP(cols));
+  int storage_order;
+  if (m.IsRowMajor) {
+    storage_order = 1;
+  } else {
+    storage_order = 0;
+  }
+  ar(CEREAL_NVP(storage_order));
 
   for (Eigen::Index i = 0; i < m.size(); i++)
     ar(m.data()[i]);
@@ -51,18 +57,18 @@ load(Archive& ar,
 {
   Eigen::Index rows;
   Eigen::Index cols;
-  int _OptionsLoaded;
-  ar(rows);
-  ar(cols);
-  ar(_OptionsLoaded);
+  int storage_order;
+  ar(CEREAL_NVP(rows));
+  ar(CEREAL_NVP(cols));
+  ar(CEREAL_NVP(storage_order));
 
   m.resize(rows, cols);
 
   for (Eigen::Index i = 0; i < m.size(); i++)
     ar(m.data()[i]);
 
   // Account for different storage orders
-  if (!(_OptionsLoaded == _Options)) {
+  if (!(storage_order == m.IsRowMajor)) {
 #if EIGEN_VERSION_AT_LEAST(3, 4, 0)
     m.transposeInPlace();
 #else

test/src/serialization.cpp

@@ -113,7 +113,6 @@ DOCTEST_TEST_CASE("test serialization of qp model, results and settings")
 {
   std::cout << "--- serialization ---" << std::endl;
   double sparsity_factor = 0.15;
-  T eps_abs = T(1e-9);
   utils::rand::set_seed(1);
   dense::isize dim = 10;